1. Field of the Invention
The present invention relates to a position measuring apparatus of a moving vehicle and particularly to an apparatus for measuring the present position of a moving vehicle utilizing reflection of light.
2. Description of the Prior Art
As the prior art, an apparatus for measuring the present position of a moving vehicle such as a car, unmanned carrier in a factory or the like is known for example in the form of an apparatus in which a moving vehicle receives the radio wave transmitted from radio wave transmitting stations installed at a plurality of locations on the ground so that the present position of the moving vehicle is calculated based on the receiving direction and other data.
Such a position measuring apparatus using a radio wave requires a plurality of transmitters, which involves a disadvantage that the manufacturing cost becomes high. Another disadvantage is that frequent inspection or maintenance is required in order to always assure normal operation of such transmitters. Particularly if the transmitters are used in the open air, the environmental conditions of the transmitters become severe and accordingly inspection or maintenance thereof will be required with excessively high frequency. In addition, since such a position measuring apparatus as described above uses a radio wave, another problem is involved that the apparatus needs to comply with the regulations of the Electric Wave Law or it is exposed to the influence of radio noise.